From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754581AbZHFLqD (ORCPT ); Thu, 6 Aug 2009 07:46:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753069AbZHFLqD (ORCPT ); Thu, 6 Aug 2009 07:46:03 -0400 Received: from mx2.redhat.com ([66.187.237.31]:45407 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752836AbZHFLqB (ORCPT ); Thu, 6 Aug 2009 07:46:01 -0400 Date: Thu, 6 Aug 2009 12:45:50 +0100 From: Alasdair G Kergon To: Mark McLoughlin Cc: device-mapper development , Jens Axboe , Rusty Russell , linux-kernel , virtualization , Mikulas Patocka Subject: Re: [dm-devel] [PATCH] block: silently error unsupported empty barriers too Message-ID: <20090806114550.GL29899@agk-dp.fab.redhat.com> Mail-Followup-To: Mark McLoughlin , device-mapper development , Jens Axboe , Rusty Russell , linux-kernel , virtualization , Mikulas Patocka References: <1249557257.3721.55.camel@blaa> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1249557257.3721.55.camel@blaa> Organization: Red Hat UK Ltd. Registered in England and Wales, number 03798903. Registered Office: Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE. User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 06, 2009 at 12:14:17PM +0100, Mark McLoughlin wrote: > We should error all barriers, even empty barriers, on devices like > virtio_blk which don't support them. Have you considered whether or not virtio_blk actually needs to support empty barriers? Alasdair